Cloudflare Speedtest

@cloudflare/speedtest is a JavaScript module to measure the quality of a client’s Internet connection. It's the measurement engine that powers the Cloudflare speedtest measurement application available at https://speed.cloudflare.com.

The module performs test requests against the Cloudflare edge network and relies on the PerformanceResourceTiming browser api to extract timing results. The network connection is characterized by items such as download/upload bandwidth, latency and packet loss.

Please note that measurement results are collected by Cloudflare on completion for the purpose of calculating aggregated insights regarding Internet connection quality.

Installation

Add this package to your package.json by running this in the root of your project's directory:

npm i @cloudflare/speedtest

Simple Usage

import SpeedTest from '@cloudflare/speedtest';

new SpeedTest().onFinish = results => console.log(results.getSummary());

API reference

SpeedTest is a JavaScript Class and should be instantiated with the new keyword. It's not required to pass a config object, as all items have default values.

Instantiation

new SpeedTest({ configOptions })

Config option	Description	Default
autoStart: boolean	Whether to automatically start the measurements on instantiation.	true
downloadApiUrl: string	The URL of the API for performing download GET requests.	https://speed.cloudflare.com/__down
uploadApiUrl: string	The URL of the API for performing upload POST requests.	https://speed.cloudflare.com/__up
turnServerUri: string	The URI of the TURN server used to measure packet loss.	turn.speed.cloudflare.com:50000
turnServerUser: string	The username for the TURN server credentials.	-
turnServerPass: string	The password for the TURN server credentials.	-
measurements: array	The sequence of measurements to perform by the speedtest engine. See below for the specific syntax of this option.
measureDownloadLoadedLatency: boolean	Whether to perform additional latency measurements simultaneously with download requests, to measure loaded latency (during download).	true
measureUploadLoadedLatency: boolean	Whether to perform additional latency measurements simultaneously with upload requests, to measure loaded latency (during upload).	true
loadedLatencyThrottle: number	Time interval to wait in between loaded latency requests (in milliseconds).	400
bandwidthFinishRequestDuration: number	The minimum duration (in milliseconds) to reach in download/upload measurement sets for halting further measurements with larger file sizes in the same direction.	1000
estimatedServerTime: number	If the download/upload APIs do not return a server-timing response header containing the time spent in the server, this fixed value (in milliseconds) will be subtracted from all time-to-first-byte calculations.	10
latencyPercentile: number	The percentile (between 0 and 1) used to calculate latency from a set of measurements.	0.5
bandwidthPercentile: number	The percentile (between 0 and 1) used to calculate bandwidth from a set of measurements.	0.9
bandwidthMinRequestDuration: number	The minimum duration (in milliseconds) of a request to consider a measurement good enough to use in the bandwidth calculation.	10
loadedRequestMinDuration: number	The minimum duration (in milliseconds) of a request to consider it to be loading the connection.	250
loadedLatencyMaxPoints: number	The maximum number of data points to keep for loaded latency measurements. When more than this amount are available, the latest ones are kept.	20

Attributes

Attribute	Description
results: Results	Getter of the current test results object. May yield incomplete values if the test is still running.
isRunning: boolean	Getter of whether the test engine is currently running.
isFinished: boolean	Getter of whether the test engine has finished all the measurements, and the results are considered final.

Methods

Method	Description
play()	Starts or resumes the measurements. Does nothing if the engine is already running or is finished.
pause()	Pauses the measurements. Does nothing if the engine is already paused or is finished.
restart()	Clears the current results and restarts the measurements from the beginning.

Notification Events

Event Method	Arguments	Description
onRunningChange	running: boolean	Invoked whenever the test engine starts or stops. The current state is included as a function argument.
onResultsChange	{ type: string }	Invoked whenever any item changes in the results, usually indicating the completion of a measurement. The type of measurement that changed is included as an info attribute in the function argument.
onFinish	results: Results	Invoked whenever the test engine finishes all the measurements. The final results object is included as a function argument.
onError	error: string	Invoked whenever an error occurs during one of the measurements. The error details are included as a function argument.

Measurement config

The specific measurements to be performed by the test engine (and their sequence) can be customized using the measurements config option. This should be an array of objects, each with a type field, plus additional fields specific to that measurement type.

The default set of measurements that is performed by the engine is:

[
  { type: 'latency', numPackets: 1 }, // initial latency estimation
  { type: 'download', bytes: 1e5, count: 1, bypassMinDuration: true }, // initial download estimation
  { type: 'latency', numPackets: 20 },
  { type: 'download', bytes: 1e5, count: 9 },
  { type: 'download', bytes: 1e6, count: 8 },
  { type: 'upload', bytes: 1e5, count: 8 },
  { type: 'packetLoss', numPackets: 1e3, responsesWaitTime: 3000 },
  { type: 'upload', bytes: 1e6, count: 6 },
  { type: 'download', bytes: 1e7, count: 6 },
  { type: 'upload', bytes: 1e7, count: 4 },
  { type: 'download', bytes: 2.5e7, count: 4 },
  { type: 'upload', bytes: 2.5e7, count: 4 },
  { type: 'download', bytes: 1e8, count: 3 },
  { type: 'upload', bytes: 5e7, count: 3 },
  { type: 'download', bytes: 2.5e8, count: 2 }
]

Here are the fields available per measurement type:

latency

Field	Required	Description	Default
numPackets: number	yes	The number of latency GET requests to perform. These requests are performed against the download API with bytes=0, and then the round-trip time-to-first-byte timing between requestStart and responseStart is extracted.	-

download / upload

Each of these measurement sets are bound to a specific file size. The engine follows a ramp-up methodology per direction (download or upload). Whenever there are multiple measurement sets (with increasing file sizes) for a direction, the engine will keep on performing them until it reaches the condition specified by bandwidthMinRequestDuration, at which point further sets in the same direction are ignored.

Field	Required	Description	Default
bytes: number	yes	The file size to request from the download API, or post to the upload API. The bandwidth (calculated as bits per second, or bps) for each request is calculated by dividing the transferSize (in bits) by the request duration (excluding the server processing time).	-
count: number	yes	The number of requests to perform for this file size.	-
bypassMinDuration: boolean	no	Whether the bandwidthMinRequestDuration check should be ignored, and the engine is instructed to proceed with the measurements of this direction in any case.	false

packetLoss

Packet loss is measured by submitting a set of UDP packets to a WebRTC TURN server in a round-trip fashion, and determining how many packets do not arrive. The submission of these packets can be done in a batching method, in which there's a sleep time in between batches.

Field	Required	Description	Default
numPackets: number	no	The total number of UDP packets to send.	100
responsesWaitTime: number	no	The interval of time (in milliseconds) to wait after the latest packet reception before determining the measurement as complete, and all non-returned packets as lost.	5000
batchSize: number	no	The number of packets in a batch. If this value is higher than numPackets there will be only one batch.	10
batchWaitTime: number	no	How long to wait (in milliseconds) between batches.	10
connectionTimeout: number	no	Timeout for the connection to the TURN server.	5000

Results object

An instance object used to access the results of the speedtest measurements. The following methods are available on this object:

Method	Description
getSummary()	Returns a high-level summary object with the computed results from the performed measurements.
getUnloadedLatency()	Returns the reduced value of the connection latency while at idle. Requires at least one latency measurement.
getUnloadedJitter()	Returns the connection jitter while at idle. Jitter is calculated as the average distance between consecutive latency measurements. Requires at least two latency measurements.
getUnloadedLatencyPoints()	Returns an array with all the latencies measured while at idle. Includes one value per measurement in sequence.
getDownLoadedLatency()	Returns the reduced value of the connection latency while loaded in the download direction. Requires measureDownloadLoadedLatency to be enabled.
getDownLoadedJitter()	Returns the connection jitter while loaded in the download direction. Requires measureDownloadLoadedLatency to be enabled, and at least two loaded latency measurements.
getDownLoadedLatencyPoints()	Returns an array with all the latencies measured while loaded in the download direction. Includes one value per loaded measurement in sequence. Requires measureDownloadLoadedLatency to be enabled.
getUpLoadedLatency()	Returns the reduced value of the connection latency while loaded in the upload direction. Requires measureUploadLoadedLatency to be enabled.
getUpLoadedJitter()	Returns the connection jitter while loaded in the upload direction. Requires measureUploadLoadedLatency to be enabled, and at least two loaded latency measurements.
getUpLoadedLatencyPoints()	Returns an array with all the latencies measured while loaded in the upload direction. Includes one value per loaded measurement in sequence. Requires measureUploadLoadedLatency to be enabled.
getDownloadBandwidth()	Returns the reduced value of the download bandwidth (in bps). Requires at least one download measurement, longer than the bandwidthMinRequestDuration threshold.
getDownloadBandwidthPoints()	Returns an array with all the download measurement results. Each item will include the following fields: { bytes, bps, duration, ping, measTime, serverTime, transferSize }.
getUploadBandwidth()	Returns the reduced value of the upload bandwidth (in bps). Requires at least one upload measurement, longer than the bandwidthMinRequestDuration threshold.
getUploadBandwidthPoints()	Returns an array with all the upload measurement results. Each item will include the following fields: { bytes, bps, duration, ping, measTime, serverTime, transferSize }.
getPacketLoss()	Returns the reduced value of the measured packet loss ratio (between 0 and 1). Requires a packetLoss measurement set.
getPacketLossDetails()	Returns an object with the details of the packet loss measurement. Includes the following fields: { packetLoss, totalMessages, numMessagesSent, lostMessages }. Requires a packetLoss measurement set.
getScores()	Returns the computed AIM scores that categorize the quality of the network connection according to use cases such as streaming, gaming or real-time communications. This score is only available after the engine has finished performing all of the measurements.